Plant monitoring apparatus and storage medium

ABSTRACT

A plant monitoring apparatus and a storage medium which allow engineering efficiency and data reliability to be improved are provided. There are disposed TAG databases  11   a  and  11   b  which store, according to an identifier, fixed parameters which are shared by a monitoring device  2  and a controlling device  3  composing the plant monitoring apparatus  1  and which are correlated with each input point. A distributing means  8  distributes fixed parameters edited by a database editing means  7  to both the monitoring device  2  and the controlling device  3  at a time.

FIELD OF THE INVENTION

[0001] The present invention relates to a plant monitoring apparatus anda storage medium, in particular, to those suitable for transmitting andreceiving process information through a network.

DESCRIPTION OF THE RELATED ART

[0002] As plants become large and complicated, the number of input andoutput points of conventional plant monitoring apparatuses amounts toseveral ten thousands. Data of point information of several tenthousands is manually and centrally managed. In addition, as plantsbecome large and complicated, the roles of each functional device arecomplicated and tangled. Consequently, an engineering operation whichintegrates those functional devices and accomplishes a monitoringfunction for a plant is becoming complicated.

[0003] For example, although there is fixed information shared by amonitoring device and a controlling device which compose a plantmonitoring apparatus, a database is created by manually linking thosecommon items.

[0004] In the controlling device, a point state (normal or abnormal) asan element of input point data and a process value are discretelyhandled and asynchronously processed. Thus, when these data are handledin the monitoring apparatus, a point state and a process value arereceived from the controlling device through a network. A point stateand a process value for each input point are collected in the monitoringdevice.

[0005] When data of all points of a plant is distributed to themonitoring device at a predetermined transmission interval, as the scaleof the plant becomes large, the amount of transmission data tends toincrease. To reduce the load imposed on the network, the transmissioninterval is prolonged.

[0006] However, when fixed information shared by the monitoring deviceand the controlling device, which compose the plant monitoringapparatus, is manually linked and a database for the fixed informationis created, if the shared data is changed, the database should be editedfor each of the monitoring device and the controlling device. Thus, ifthe plant monitoring apparatus is composed of many devices, databaseswhich have the same content should be changed many times. Thus, it istroublesome. In addition, if different parameters are mistakenly inputinstead of same parameters, the reliability of the monitoring work couldbe lost.

[0007] When a point state and a process value, which are separatelyhandled in the controlling device, are received through the network andthe point state and the process value are collected by the monitoringdevice, depending on a sampling timing and a point state change, datamay be temporarily inconsistent. Consequently, data of the controllingdevice might conflict with data of the monitoring device. As a result,the monitoring operation might be adversely affected.

[0008] To reduce the load imposed on the network during datatransmission, if the transmission interval is prolonged, the real-timeproperty of the monitoring operation will be adversely deteriorated.

[0009] In addition, if a defect takes place on a transmission path suchas a network, an event notification is not distributed to the monitoringdevice. As a result, the plant monitoring apparatus might not recognizeoccurrence of the defect.

SUMMARY OF THE INVENTION

[0010] Therefore, an object of the present invention is to provide aplant monitoring apparatus and a storage medium which allow thereliability of data to be improved.

[0011] To solve the forgoing problem, claim 1 of the present inventionis a plant monitoring apparatus comprising a common parameter settingmeans for setting a common parameter shared by a plurality of devices,and a distributing means for distributing the common parameter to theplurality of devices.

[0012] Thus, a common parameter used in a plurality of devices can bechanged by one edit operation. Since it is not necessary to repeatedlychange a common parameter for each device, the engineering efficiency ofthe plant can be improved. In addition, a common parameter can beprevented from being inconsistent in each device due to an inputmistake. As a result, the reliability of the monitoring operation can beimproved.

[0013] It is preferred for the apparatus to further comprise a TAGdatabase for each of the devices configured to store the commonparameter; and a device database for each of the devices configured tostore a parameter individual for each of the devices.

[0014] Thus, a common parameter can be set to a plurality of devices byone distributing process. In addition, an independent process can bealso performed for each device.

[0015] Claim 3 of the present invention is a plant monitoring apparatuscomprising a process information grouping means for grouping the processinformation according to an identifier unit, and a transmitting meansfor transmitting the grouped process information at a time.

[0016] Thus, the side to which process information is distributed doesnot need to perform an operation for correlating the process informationseparately transmitted. In addition, process information distributed toa plurality of locations can be uniformly correlated. Thus, since theconsistency of data between for example the controlling device and themonitoring device is improved, the reliability of the monitoringoperation is also improved.

[0017] It is preferred for the apparatus to further comprise a means forcausing the process information to be consistent according to anidentifier unit.

[0018] Thus, while a plurality of pieces of data handled between theside that distributes information and the side to which information isdistributed is consistent, processes can be distributively monitoredthrough the network.

[0019] It is preferred for the apparatus to further comprise a statechange detecting means for detecting a state change of the plantaccording to an identifier unit. It is preferred for the transmittingmeans to transmit current process information only when a state changeof the plant has been detected.

[0020] Thus, when the plant state does not change, data is nottransmitted. Thus, when the plant scale becomes large and the amount oftransmission data increases, the load imposed on the network can bereduced without a deterioration of real-time property of the monitoringoperation.

[0021] It is preferred for the state change detecting means to comprisea change amount detecting means for detecting a change amount of a plantvalue according to an identifier unit. It is preferred for thetransmitting means to transmit current process information only when thechange amount exceeds a specified value.

[0022] Thus, even when a change of a plant value that is caused by ameasurement error or the like, has occurred, data is not transmitted. Asa result, the load imposed on the network can be further reduced withouta deterioration of the monitoring function.

[0023] It is preferred for the apparatus to further comprise a countingmeans for counting transmissions of event notification according to anidentifier unit. It is preferred for the transmitting means to add thetransmission count to the event notification and transmit the eventnotification with the transmission count.

[0024] Thus, a lost event notification can be detected on the side towhich information is distributed. When data cannot be transmitted to theside to which information is distributed, it can recognize occurrence ofa defect.

[0025] It is preferred for the apparatus to further comprise a receivingmeans for receiving an event notification to which the transmissioncount has been added and determining means for determining a receptionstate of the event notification, based on a result from comparingbetween the transmission count of the event notification and a receptioncount of the event notification.

[0026] Thus, when the transmission count of the event notification doesnot match the reception count of the event notification, a lost eventnotification can be detected on the side to which information isdistributed. Consequently, even if a low reliability transmission pathis used, the reliability of data transmission can be improved without asacrifice of high speed data transmission.

[0027] It is preferred for the apparatus to further comprise aretransmission requesting means for requesting the retransmission of theevent notification according to the reception state.

[0028] Thus, when an event notification has been lost, the eventnotification can be securely received later. As a result, the monitoringfunction on the side to which information is distributed can beprevented from deteriorating.

[0029] In addition, the present invention is a computer readable storagemedium on which a program has been stored, the program causing thecomputer to execute the steps of linking a process value with meaninginformation indicating a meaning of the process value, and transmittingthe process value and the meaning information at a time.

[0030] Thus, not only a process value is received as a numeric value,but also the meaning of the process value can be received. Consequently,the side to which information is distributed can know what the processvalue represents. As a result, the monitoring performance of the plantstate can be improved.

BRIEF DESCRIPTION OF DRAWINGS

[0031]FIG. 1 is a block diagram showing the structure of a plantmonitoring apparatus according to a first embodiment of the presentinvention.

[0032]FIG. 2 is a schematic diagram showing an example of the structureof a TAG database; FIG. 2 is a schematic diagram showing an example ofthe structure of a device database.

[0033]FIG. 3 is a schematic diagram showing an example of a databaseedit screen according to the first embodiment of the present invention.

[0034]FIG. 4 is a block diagram showing the structure of a plantmonitoring apparatus according to a second embodiment of the presentinvention.

[0035]FIG. 5 is a timing chart showing a state transition of processdata according to the second embodiment of the present invention.

[0036]FIG. 6 is a flow chart showing a grouping process of process dataaccording to the second embodiment of the present invention.

[0037]FIG. 7 is a block diagram showing the structure of a plantmonitoring apparatus according to a third embodiment of the presentinvention.

[0038]FIG. 8 is a timing chart for explaining a determining method of anevent notification according to the third embodiment of the presentinvention.

[0039]FIG. 9 is a flow chart showing a state change detecting processfor process data according to the third embodiment of the presentinvention.

[0040]FIG. 10 is a block diagram showing the structure of a plantmonitoring apparatus according to a fourth embodiment of the presentinvention.

[0041]FIG. 11 is a timing chart for explaining a detecting method of alost event notification according to the fourth embodiment of thepresent invention.

[0042]FIG. 12 is a block diagram showing the structure of a plantmonitoring apparatus according to a fifth embodiment of the presentinvention.

[0043]FIG. 13 is a flow chart for showing a data acquiring method upondetection of a lost event notification according to the fifth embodimentof the present invention.

[0044]FIG. 14 is a block diagram showing a structure on which softwarethat accomplishes a plant monitoring apparatus according to anembodiment of the present invention acts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] Next, a plant monitoring apparatus according to an embodiment ofthe present invention will be explained with reference to theaccompanying drawings. FIG. 1 is a block diagram showing the structureof a plant monitoring apparatus according to a first embodiment of thepresent invention.

[0046] Referring to FIG. 1, a plant monitoring apparatus 1 that monitorsa plant comprises a monitoring device 2 and a controlling device 3,mainly. The monitoring device 2 has a man-machine interface functionwith which the user interactively operates the plant. The controllingdevice 3 exchanges data with the plant. The plant monitoring apparatus 1further comprises a network 4, a notifying means 5, an input/outputmeans 6, a database editing means 7, and a distributing means 8. Thenetwork 4 connects the monitoring device 2 with the controlling device3. The notifying means 5 notifies the operator of an alarm. Theinput/output means 6 inputs and outputs data to and from the plant. Thedatabase editing means 7 edits a database. The distributing means 8distributes an obtained result from editing the database to themonitoring device 2 and the controlling device 3.

[0047] In addition, the monitoring device 2 is provided with amonitoring portion 9. The monitoring portion 9 monitors the plant basedon plant information that is sent from the controlling device 3. Thecontrolling device 3 is provided with a data input/output portion 10which transmits data retrieved from the plant to the monitoring device 2through the network 4. The monitoring device 2 and the controllingdevice 3 are provided with TAG databases 11 a and 11 b, device databases12 a and 12 b, and database updating means 13 a and 13 b, respectively.The TAG databases 11 a and 11 b store fixed parameters of each inputpoint which are shared by the monitoring device 2 and controlling device3 according to each TAGID as an unit, respectively. The device databases12 a and 12 b store, using each TAGID as a key, device information thatis dedicated for each device, respectively. The database updating means13 a and 13 b update contents of the TAG databases 11 a and 11 b andcontents of the device databases 12 a and 12 b, respectively.

[0048]FIG. 2A is a schematic diagram showing an example of the structureof the TAG databases 11 a and 11 b. In the TAG databases 11 a and 11 bthere is set parameters that are shared in the plant monitoringapparatus 1 according to each TAGID as an unit. Namely, in the TAGdatabases 11 a and 11 b there can be set information and so forth thatshould be totally managed in the system. For example, a valid rangewidth of a process value, the presence or absence of an alarm process,an indispensable limit value in the case that the alarm process ispresent, and so forth can be set according to each TAGID as an unit. Thelimit value may have steps. The limit value may have an upper limitand/or a lower limit. Each TAGID may be determined by the operator.Alternatively, each TAGID may be prepared by the system.

[0049]FIG. 2B is a schematic diagram showing an example of the structureof the device databases 12 a and 12 b. As shown in FIG. 2B, parameterswhich are dedicated for the monitoring device 2 and the controllingdevice 3 are respectively set to the device databases 12 a and 12 b,using each TAGID as a key. For example, a display range of a bar chartof process values displayed on a displaying device of the notifyingmeans 5 can be set to the device database 12 a of the monitoring device2.

[0050] A display range used on the displaying device is required for themonitoring device 2, but not for the controlling device 3, which inputsand outputs data. Thus, a display range and so forth used for thedisplaying device are set to only the device database 12 a. Informationthat is not necessary for the controlling device 3 is not set the devicedatabase 12 b. As a result, the storage capacity of the device database12 b can be reduced.

[0051] On the other hand, information peculiar to inputting andoutputting data, for example conversion information necessary forconverting a voltage value and a count value which are input from asensor of each portion of the plant can be set to the device database 12b of the controlling device 3. The conversion information used in thecontrolling device 3 is necessary for the controlling device 3, but notfor the monitoring device 2, which is a human interface with theoperator. Thus, the conversion information and so forth used in thecontrolling device 3 are set to only the device database 12 b.Information that is not necessary for the monitoring device 2 is not setto the device database 12 a. As a result, the storage capacity of thedevice database 12 a can be reduced.

[0052] To update the contents of the TAG databases 11 a and 11 b and thecontents of the device databases 12 a and 12 b in the plant monitoringapparatus 1 shown in FIG. 1, the operator interactively operates thedatabase editing means 7 so as to evoke the database edit screen.

[0053]FIG. 3 is a schematic diagram showing an example of a databaseedit screen according to the first embodiment of the present invention.On the database edit screen, parameters that can be set according to thedistinction between common information and device information aredisplayed regarding each TAG. For example, to edit parameters regardingTAGID #n, the operator selects TAGID #n on the database edit screen ofthe database editing means 7. Then, set items of common parameters, setitems of parameters of the monitoring device, and set items ofparameters of the input/output device regarding TAGID #n are displayed.When these set items are displayed, the operator edits them.

[0054] After the operator has edited the set items, the editedparameters are distributed to each target devices automatically or bythe request of the operator.

[0055] After the operator has edited the common parameters, for example,when he or she designates ‘All System’ as the destination ofdistribution, the distributing means 8 distributes the edited commonparameters to both the monitoring device 2 and the controlling device 3.When the common parameters have been distributed, the database updatingmeans 13 a and 13 b store the contents of the distributed commonparameters to the TAG databases 11 a and 11 b, respectively.

[0056] After the operator has edited the parameters for the monitoringdevice, when he or she designates ‘Monitoring Device’ as the destinationof distribution, the distributing means 8 distributes the editedparameters for the monitoring device to the monitoring device 2. Afterthe parameters for the monitoring device have been distributed, thedatabase updating means 13 a stores the contents of the distributedparameters for the monitoring device to the device database 12 a.

[0057] After the operator has edited the parameters for the input/outputdevices, when he or she designates ‘Input/Output Device’ as thedestination of distribution, the distributing means 8 distributes theedited parameters for the input/output device to the controlling device3. After the parameters for the input/output device have beendistributed, the database updating means 13 b stores-the contents of thetransmitted parameters for the input/output device to the devicedatabase 12 b.

[0058] When fixed information shared in the system is grouped as acommon parameter, the place of the parameter in the system can beclarified. Thus, the operator can easily distinguish parameters sharedin the system from those discretely used for each device. Whenparameters shared in the system are changed, the operator can easilyknow which parameters he or she should change. As a result, inputmistakes can be reduced and thereby the system can be effectivelyoperated.

[0059] In addition, when the contents of a plurality of TAG databases 11a and 11 b are changed, common parameters can be edited and distributedat a time. As a result, the engineering efficiency of the plant can beimproved.

[0060] In addition, it can be prevented that although the monitoringdevice 2 and the controlling device 3 are simultaneously used differentvalues are set to the monitoring device 2 and the controlling device 3.Thus, even if a complicated operation such as a change of a systemcommon parameter is performed, the operation can be easily performed.

[0061] Furthermore, when information necessary for the monitoring device2 and information necessary for the controlling device 3 are separatelyadded thereto, information necessary for only the monitoring device 2can be stored by only the monitoring device 2, whereas informationnecessary for only the controlling device 3 can be stored by thecontrolling device 3. Thus, the storage capacity can be reduced.

[0062] Moreover, each parameter can be set to each database according toan application. Each parameter can be edited and distributed accordingto a purpose thereof. As a result, the engineering efficiency of theplant can be improved.

[0063] In FIG. 1, after the TAG databases 11 a and 11 b and the devicedatabases 12 a and 12 b have been set, the data input/output portion 10captures data of each portion of the plant through the input/outputmeans 6. Further, the data input/output portion 10 makes reference tothe content of the device database 12 b and converts the captured plantdata into a process value. The converted process value is sent to themonitoring device 2 through the network 4.

[0064] In addition, the data input/output portion 10 can make referenceto the content of the TAG database 11 b and determine whether or not theconverted process value is in a valid range. As a result, the datainput/output portion 10 can determine a point quality (normal/abnormalof the point state) of the process value. Further, the data input/outputportion 10 can compare the converted process value with the limit valueto determine an alarm state.

[0065] After the monitoring device 2 has received a process value fromthe controlling device 3, the monitoring portion 9 makes reference tothe content of the TAG database 11 a to determine the point quality(normal/abnormal of the point state) of the process value and/or thealarm state. Then, the monitoring portion 9 makes reference to thecontent of the device database 12 a to convert the determined resultinto a display format designated by the operator, and to notify theoperator of the determined result through the notifying means 5.

[0066] In such a manner, the TAG databases 11 a and 11 b are disposed inboth the controlling device 3 and the monitoring device 2. Themonitoring device 2 and the controlling device 3 independently determinea point quality and an alarm state. Thus, even if only a process valueis sent from the controlling device 3 to the monitoring device 2, themonitoring device 2 can determine an alarm. As a result, when themonitoring device 2 monitors the plant, the load imposed on the network4 can be reduced.

[0067] Next, with reference to the accompanying drawings, a plantmonitoring apparatus according to a second embodiment of the presentinvention will be described.

[0068] In the plant monitoring apparatus 1 shown in FIG. 1, since commonparameters between the controlling device 3 and the monitoring device 2have been set to the TAG databases 11 a and 11 b, a resultantdetermination of a point quality, an alarm state, and so forth by thecontrolling device 3 must match those by the monitoring device 2.

[0069] However, it takes a time for a process value to be sent from thecontrolling device 3 to the monitoring device 2. Thus, the currentprocess value of the controlling device 3 may not match the currentprocess value of the monitoring device 2. Consequently, when a pointquality, an alarm state, and so forth are determined according to thecurrent process values in the monitoring device 2 and in the controllingdevice 3, the determined results may be different. Thus, the data cannotbe consistent between the monitoring device 2 and the controlling device3.

[0070] To solve such a problem, according to the second embodiment ofthe present invention, a current process value, a point quality thereofand/or an alarm state, and so forth are packaged. The packaged data istreated as one unit of data.

[0071]FIG. 4 is a block diagram showing the structure of a plantmonitoring apparatus according to the second embodiment of the presentinvention.

[0072] In FIG. 4, a plant monitoring apparatus 21 which monitors a plantcomprises a monitoring device 22, a controlling device 23, a network 24,a notifying means 25, and an input/output means 26. The monitoringdevice 22 has a man-machine interface function with which the userinteractively operates the plant. The controlling device 23 exchangesdata with the plant. The network 24 connects the monitoring device 22with the controlling device 23. The notifying means 25 notifies theoperator of a message. The input/output means 26 inputs and outputs datato and from the plant.

[0073] The monitoring device 22 is provided with a monitoring portion 27which monitors the plant according to plant information sent from thecontrolling device 23. The controlling device 23 is provided with a datainput/output portion 28 and a TAG data processing portion 29. The datainput/output portion 28 sends data captured from the plant to the TAGdata processing portion 29. The TAG data processing portion 29 collectsprocess data, which is input from the plant, as TAG variable data ateach sampling interval and creates meaningful monitor information foreach input point according to each TAGID as an unit. TAG fixedinformation databases 30 a and 30 b are disposed in the monitoringdevice 22 and the controlling device 23, respectively. The TAG fixedinformation databases 30 a and 30 b store fixed parameters of each inputpoint which are shared by the monitoring device 22 and the controllingdevice 23 according to each TAGID as an unit. For example, a valid rangewidth of a process value, the presence or absence of an alarm process,an indispensable limit value in the case that the alarm process ispresent, and so forth for can be set to the TAG fixed informationdatabases 30 a and 30 b according to each TAGID as an unit.

[0074] In the plant monitoring apparatus 21, the data input/outputportion 28 collects process data which are output according to eachpoint from each sensor of each portion of the plant through theinput/output means 26 at each sampling interval. Then, a process valueand a point state (input point state) are obtained from the processdata. The TAG data processing portion 29 is notified of the processvalue and the point state (input point state). Process data which areinput according to each point from the plant includes an analog pointand a contact point. An analog point is composed of a process value(analog value) and a point quality (normal/abnormal of point state). Acontact point is composed of a process value (contact STE) and a pointquality (normal/abnormal of point state).

[0075] After the TAG data processing portion 29 has been notified by thedata input/output portion 28 of a process value and a point state (inputpoint state), the TAG data processing portion 29 obtains the collectionresult including the process value, the point state, and the alarm state(normal/alarm) according to the content of the TAG fixed informationdatabase 30 b. After the collection result has been obtained, the TAGdata processing portion 29 groups the collection result including thepoint state (normal/abnormal), the process value, and the alarm state(normal/alarm) as a current state for each point and notifies themonitoring device 22 of the grouped data as TAG current data. After themonitoring device 22 has been notified of the TAG current data, themonitoring portion 27 notifies the notifying means 25 of the alarm stateand so forth contained in the TAG current data to inform the operator ofoccurrence of a defect of the plant.

[0076] Here, after the monitoring device 22 has been notified of the TAGcurrent data, the monitoring portion 27 can also make reference to thecontent of the TAG fixed information database 30 a to determine analarm.

[0077] However, since a process value collected by the controllingdevice 23 is transferred along with a point state (normal/abnormal) ofthe process value and an alarm state (normal/alarm) of the processvalue, the monitoring device 22 does not need to determine an alarm. Asa result, the inconsistence between the alarm determination result ofthe monitoring device 22 and the alarm determination result of thecontrolling device 23 can be prevented. Consequently, the consistencybetween the alarm determination result of the monitoring device 22 andthe alarm determination result of the controlling device 23 can bemaintained. Accordingly, the reliability of the alarm determination canbe improved.

[0078] Next, an example of the process data collecting method in thecase that a point state has changed will be explained.

[0079]FIG. 5 is a timing chart showing a state transition of processdata according to the second embodiment of the present invention. Now,it is assumed that upper limit value=100.0 for determining an alarmstate of a process value has been set to the TAG fixed informationdatabase 30 b.

[0080] It is assumed that at time t1 data of process value=90.0 andpoint state=normal has been sampled. In this case, since the point stateis normal, the TAG data processing portion 29 treats the process valueas valid data. As a result, the TAG data processing portion 29determines that the collection result of the point state should benormal and that the collection result of the process value should be90.0. Since process value=90.0 does not exceed the limit value, the TAGdata processing portion 29 determines that the collection result of thealarm state should be normal.

[0081] Next, it is assumed that at time t2 data of process value=90.0and point state=abnormal has been sampled. In this case, since theprocess value is normal but the point state is abnormal, the TAG dataprocessing portion 29 determines that the collection result of the pointstate should be abnormal, that the collection result of the processvalue should be invalid, and that the collection result of the alarmstate should be invalid.

[0082] Next, it is assumed that at time t3 data of process value=110.0and point state=normal has been sampled. In this case, since the pointstate is normal, the TAG data processing portion 29 determines that theprocess value should be valid, that the collection result of the pointstate should be normal, and that the collection result of the processvalue should be 110.0. In addition, since process value=110.0 exceedsthe upper limit value, the TAG data processing portion 29 determinesthat the collection result of the alarm state should be alarm.

[0083] Next, it is assumed that at time t4 data of process value=invalidand point state=abnormal has been sampled. In this case, since the pointstate is abnormal, the TAG data processing portion 29 determines thatthe collection result of the point state should be abnormal, that thecollection result of the process value should be invalid, and that thecollection result of the alarm state should be invalid.

[0084] After the collection results including the process value, thepoint state, and the alarm state have been obtained at each samplinginterval, the TAG data processing portion 29 groups the collectionresults and sends the grouped data as one piece of data to themonitoring device 22.

[0085] When a process value, a point quality, and the result of an alarmprocess are asynchronously sent to the monitoring device 22, in spite ofthe abnormality of the point the process value or an alarm may bedisplayed. For example, when only a process value is sent to themonitoring device 22 at time t2 shown in FIG. 5, the monitoring device22 determines that process value=90 and alarm state=normal although theprocess value and the alarm state should be treated as an invalid valueand an invalid state because the point state is abnormal. Thus, theoperator will be informed of incorrect information.

[0086] To prevent such a problem, collection results including a processvalue, a point state, and an alarm state are sent as one piece of datato the monitoring device 22. As a result, the determination results ofthe monitoring device 22 and the controlling device 23 can beconsistent.

[0087]FIG. 6 is a flow chart showing a grouping process for process dataaccording to the second embodiment of the present invention. In FIG. 6,when process data is input to the TAG data processing portion 29 throughthe data input/output portion 28, the TAG data processing portion 29performs a data receiving process (at step S1). In the data receivingprocess, the TAG data processing portion 29 makes reference to thecontent of the TAG fixed information database 30 b to determine whetheror not the current process value is in the valid range, and to determinea point quality (normal/abnormal of point state).

[0088] Next, the TAG data processing portion 29 performs a TAG fixedinformation acquiring process (at step S2). In the TAG fixed informationacquiring process, the TAG data processing portion 29 acquires thepresence/absence of the alarm process from the TAG fixed informationdatabase 30 b. When the alarm process is present, the TAG dataprocessing portion 29 also acquires a limit value.

[0089] Next, the TAG data processing portion 29 determines whether ornot the point state is abnormal (at step S3). When the point state isabnormal, the TAG data processing portion 29 performs a data collectingprocess (1) (at step S4). In the data collecting process (1), the TAGdata processing portion 29 adds the current process value and pointquality to the TAG fixed information to create TAG current data.

[0090] In contrast, when the determination result at step S3 representsthat the point state is not abnormal, the TAG data processing portion 29determines whether or not the alarm process is present (at step S5).When the alarm process is present, the TAG data processing portion 29performs an alarm determining process (at step S6). Thereafter, the TAGdata processing portion 29 performs a data collecting process (2) (atstep S7). In the data collecting process, the TAG data processingportion 29 compares the current process value with the limit value so asto determine an alarm state. In the data collecting process (2), the TAGdata processing portion 29 adds the current process value, the pointquality, and the alarm state to the TAG fixed information to create TAGcurrent data.

[0091] In contrast, when the determination result at step S5 representsthat the alarm process is absent, the TAG data processing portion 29performs the forgoing data collecting process (1) (at step S8).

[0092] As mentioned above, the TAG data processing portion 29, whichgroups input point data such process values and input point states whichare input from the plant as meaningful data and treats the grouped dataas TAG current data, is disposed. The TAG data processing portion 29performs the data collecting process for each point (input point),manages the collected data as TAG current data, and supplies the TAGcurrent data to the monitoring portion 27. As a result, the consistencybetween each piece of data to be monitored can be improved.Consequently, the monitor performance can be improved.

[0093] Next, with reference to the accompanying drawings, a plantmonitoring apparatus according to a third embodiment of the presentinvention will be described.

[0094] The plant monitoring apparatus 21 shown in FIG. 4 groupsinformation of a current process value, a point quality thereof, analarm state thereof, and so forth and transfers the grouped data as onepiece of TAG current data. Thus, the consistency of data between thecontrolling device 23 and the monitoring device 22 can be improved.

[0095] However, since various information together with a process valueand a point quality have been added to the TAG current data, the amountof information of the TAG current data is larger than that of the casethat the process value, the point quality, and so forth are separatelyhandled. Thus, when a current process value collected at each samplingis transferred as TAG current data, the load imposed on the network 24becomes large.

[0096] Thus, according to the third embodiment of the present invention,a state change of TAG current data is monitored. Only when the state ofthe TAG current data has changed, the TAG current data is transferred.As a result, the load imposed on the network 24 can be reduced.

[0097]FIG. 7 is a block diagram showing the structure of a plantmonitoring apparatus according to the third embodiment of the presentinvention. In FIG. 7, a plant monitoring apparatus 41 is composed of astate change detecting portion 43 together with the structure of theplant monitoring apparatus 21 shown in FIG. 4. The state changedetecting portion 43 detects a state change of TAG current data anddetermines, according to the state change, whether to notify themonitoring device 22 of the TAG current data.

[0098] Specifically, when the state change detecting portion 43 isnotified of the TAG current data created by the TAG data processingportion 29, the state change detecting portion 43 stores the TAG currentdata. The state change detecting portion 43 compares the TAG currentdata of the latest notification with the TAG current data of theprevious notification. Only when the result from comparing representsthat one of the following conditions (a) to (c) has been satisfied, thestate change detecting portion 43 notifies the monitoring device 22 ofthe TAG current data of the latest notification through the network 24.In addition, the state change detecting portion 43 stores the TAGcurrent data of the latest notification as the TAG current data of theprevious notification.

[0099] (a) if a change of a point state has been detected (namely, thepoint state has been changed from normal to abnormal or from abnormal tonormal),

[0100] (b) if a change of an alarm state has been detected (namely, thealarm state has been changed from normal to alarm or from alarm tonormal), and

[0101] (c) if a point state is normal and a process value has changedfor a predetermined value (a mask value for a change amount of a processvalue) or more (in other words, absolute value of changeamount>predetermined value).

[0102] The predetermined value may be pre-stored in the TAG fixedinformation database 30 b.

[0103] In contrast, if any one of (a) to (c) has not been satisfied, thestate change detecting portion 43 discards the TAG current data of thelatest notification. In other words, the state change detecting portion43 does not notify the monitoring device 22 of the TAG current data ofthe latest notification. In addition, the state change detecting portion43 does not store the TAG current data of the latest notification as theTAG current data of the previous notification.

[0104] Next, a concrete example of the process of the state changedetecting portion 43 will be explained.

[0105]FIG. 8 is a timing chart for explaining an event notificationdetermining method according to the third embodiment of the presentinvention. In this example, it is assumed that the TAG data processingportion 29 notifies the state change detecting portion 43 of a processvalue, an alarm state, and a point state as TAG current data at each ofsampling timings t0, t1, t2, . . . . It is further assumed that timingt0 is an initial state and that the predetermined value is 10.0.

[0106] At timing to process value=89.0, alarm state=normal, and pointstate=normal. The state change detecting portion 43 stores these data.

[0107] Next, at timing t1 process value=98.5, alarm state=normal, andpoint state=normal. The state change detecting portion 43 compares theprocess value, the alarm state, and the point state at timing t0 withthe process value, the alarm state, and the point state at timing t1,respectively. In this case, the alarm state and the point state have notchanged. The process value has changed for 98.5−89.0=9.5. Thus, thechange amount of the process value is smaller than the predeterminedvalue 10.0. Therefore, the state change detecting portion 43 does notnotify the monitoring device 22 of an event. In addition, the statechange detecting portion 43 maintains the data at timing t0 as the TAGcurrent data of the previous notification.

[0108] As mentioned above, even if a process value has changed, when thechange amount of the process value does not exceed the predeterminedvalue, an event notification is not performed. Consequently, also in thecase that a process value is displayed on real time basis, the displayedvalue can be prevented from fluctuating due to a delicate change of theprocess value. As a result, the monitor performance can be improved, andthe load imposed on the network 24 can be reduced.

[0109] Next, at timing t2 process value=109.5, alarm state=normal, andpoint state=normal. The state change detecting portion 43 compares theprocess value, the alarm state, and the point state at timing t0 withthe process value, the alarm state, and the point state at timing t2,respectively. In this case, the alarm state and the point state have notchanged. On the other hand, the process value has changed for109.5−89.0=20.5, which is larger than the predetermined value 10.0.Thus, the state change detecting portion 43 notifies the monitoringdevice 22 of an event. In addition, the state change detecting portion43 stores the data at timing t2 as the TAG current data of the previousnotification.

[0110] Next, at time t3 process value=115.5, alarm state=alarm, andpoint state=normal. The state change detecting portion 43 compares theprocess value, the alarm state, and the point state at timing t2 withthe process value, the alarm state, and the point state at timing t3,respectively. In this case, the point state has not changed. The processr value has changed for 115.5−109.5=6.0, which is smaller than thepredetermined value 10.0. On the other hand, the alarm state has changedfrom normal to alarm. Thus, the state change detecting portion 43notifies the monitoring device 22 of an event. In addition, the statechange detecting portion 43 stores data at timing t3 as the TAG currentdata of the previous notification.

[0111] Next, at timing t4 process value=invalid, alarm state=invalid,and point state=abnormal. The state change detecting portion 43 comparesthe process value, the alarm state, and the point state at timing t3with the process value, the alarm state, and the point state at timingt4, respectively. In this case, the point state has changed from normalto abnormal. Thus, the state change detecting portion 43 notifies themonitoring device 22 of an event. In addition, the state changedetecting portion 43 stores the data at timing t4 as the TAG currentdata of the previous notification.

[0112] Next, at timing t5 process value=116.0, alarm state=invalid, andpoint state=abnormal. The state change detecting portion 43 compares theprocess value, the alarm state, and the point state at timing t4 withthe process value, the alarm state, and the point state at timing t5. Inthis case, the point state has changed from abnormal to normal. Thus,the state change detecting portion 43 notifies the monitoring device 22of an event. In addition, the state change detecting portion 43 storesthe data at timing t5 as the TAG current data of the previousnotification.

[0113]FIG. 9 is a flow chart showing a detecting process of a statechange of process data according to the third embodiment of the presentinvention. In FIG. 9, the state change detecting portion 43 compares theTAG current data of the latest notification with the TAG current data ofthe previous notification (at step s11), and determines whether or notthe point state has changed and whether or not the alarm state haschanged (at step S12). When the results from determining represent thatthe point state has changed or that the alarm state has changed, thestate change detecting portion 43 notifies the monitoring device 22 ofthe TAG current data of the latest notification through the network 24(at step S13). In addition, the state change detecting portion 43 storesthe TAG current data of the latest notification as the TAG current dataof the previous notification (at step S14).

[0114] In contrast, when the results from determining at step S12represent that the point state has not changed and that the alarm statehas not changed, the state change detecting portion 43 determineswhether or not the process value has changed for the predetermined valueor more (at step S15). When the process value has changed for thepredetermined value or more, the state change detecting portion 43notifies the monitoring device 22 of the TAG current data of the latestnotification through the network 24 (at step S16). In addition, thestate change detecting portion 43 stores the TAG current data of thelatest notification as the TAG current data of the previous notification(at step S17).

[0115] In contrast, when the result from determining at step S15represents that the process value has not changed for the predeterminedvalue or more, the state change detecting portion 43 does not notify themonitoring device 22 of the TAG current data of the latest notification,nor does the state change detecting portion 43 store the TAG currentdata of the latest notification as the TAG current data of the previousnotification.

[0116] As mentioned above, the state change detecting portion 43determines whether or not to require an event notification at eachsampling timing. Only when the state change detecting portion 43 hasdetected a state change of the TAG current data, the state changedetecting portion 43 notifies the monitoring device 22 of an eventthrough the network 24. As a result, the load imposed on the network 24can be suppressed without a deterioration of the monitoring function ofthe monitoring device 22. Consequently, the plant can be monitored onreal time basis.

[0117] Next, with reference to the accompanying drawings, a plantmonitoring apparatus according to a fourth embodiment of the presentinvention will be explained.

[0118] In the plant monitoring apparatus 41 shown in FIG. 7, only when astate has changed, TAG current data is transferred to the monitoringdevice 22. Thus, the load imposed on the network 24 can be suppressedwithout a deterioration of the monitoring function of the monitoringdevice 22.

[0119] Here, when TCP/IP (Transmission Control Protocol/Internetprotocol) is used as a communication protocol, it can be determinedwhether or not data has been reached to a remote party. Consequently, adata communication with high reliability can be performed.

[0120] Although TCP/IP allows data to be communicated with highreliability, the data transmission rate is low. When TAG current data istransferred to many destinations, the real time performance formonitoring the plant may be sacrificed.

[0121] Thus, when TAG current data is transferred to many destinations,it is preferred to use UDP/IP (User Datagram Protocol/Internet Protocol)which has a higher transfer rate than TCP/IP.

[0122] However, when UDP/IP is used, although higher data transfer rateis accomplished, it cannot be determined whether or not data has beenreached to a remote party. Thus, the reliability of data transferbecomes low.

[0123] To solve such a problem, according to the fourth embodiment ofthe present invention, a count value is added to TAG current data. Theresultant TAG current data is transferred to a remote party. Accordingto the count value, the remote party can determine whether or not anevent notification has been lost. Consequently, the data transfer ratecan be improved without a sacrifice of the reliability of the datatransfer.

[0124]FIG. 10 is a block diagram showing the structure of the plantmonitoring apparatus according to the fourth embodiment of the presentinvention. In FIG. 10, a plant monitoring apparatus 51 is composed ofthe structure of the plant monitoring apparatus 41 shown in FIG. 7, atransmission count adding portion 55 which is disposed in a controllingdevice 53, and a count checking portion 54 which is disposed in amonitoring device 52. The transmission count adding portion 55 adds atransmission count value to a header portion of TAG current data andnotifies the monitoring device 52 of the count value through the network24. The count checking portion 54 makes reference to the header portionof the TAG current data received through the network 24, checks thetransmission count value added to the header portion, and detectswhether or not an event notification has been lost due to a networkdefect.

[0125] Specifically, when the count checking portion 54 is initiallyoperated, it requests the transmission count adding portion 55 to set acounter initial value to 0. When the transmission count adding portion55 is requested to set the counter initial value to 0, whenever thetransmission count adding portion 55 is notified by a state changedetecting portion 43 that a state has changed, the transmission countadding portion 55 increments the count value by 1, and sets the countvalue to the header portion of the TAG current data. Thereafter, thetransmission count adding portion 55 notifies the count checking portion54 of TAG current data to whose header portion the count value has beenset.

[0126] When the count checking portion 54 receives the TAG current datato which the count value has been set, the count checking portion 54makes reference to the header portion of the TAG current data andacquires the count value which has been set to the TAG current data. Thecount checking portion 54 compares the count value which has been set tothe TAG current data of the latest notification with the count valuewhich has been set to the TAG current data of the previous notification.When the difference of the count values is not +1, the count checkingportion 54 determines that an event notification has been lost andnotifies the operator that an event notification has been lost throughthe monitoring portion 27.

[0127] Next, a concrete example of processes between the transmissioncount adding portion 55 and the count checking portion 54 will beexplained.

[0128]FIG. 11 is a timing chart for explaining a lost event notificationdetecting method according to the fourth embodiment of the presentinvention. In FIG. 11, when the monitoring portion 27 is initiallyoperated, the transmission count adding portion 55 is notified by thecount checking portion 54 of an initial count value 0. The transmissioncount adding portion 55 sets count value=0.

[0129] Next, when the transmission count adding portion 55 is notifiedby the state change detecting portion 43 that a state has changed attime t(1), the transmission count adding portion 55 increments thecurrent count value=0 by 1, adds count value=1 to TAG current data, andnotifies the count checking portion 54 of count value=1. When the countchecking portion 54 receives the TAG current data, the count checkingportion 54 extracts the current count value=1 from the TAG current dataand compares the previous count value=0 with the current count value=1.When the result from comparing represents that the difference of thecount values is 1, the count checking portion 54 determines that datashould have been normally transferred.

[0130] Next, when the transmission count adding portion 55 is notifiedby the state change detecting portion 43 that a state has changed attime t(2), the transmission count adding portion 55 increments thecurrent count value=1 by 1, adds count value=2 to the TAG current data,and notifies the count checking portion 54 of count value=2. When thecount checking portion 54 receives the TAG current data, the countchecking portion 54 extracts the current count value=2 from the TAGcurrent data and compares the previous count value=1 with the currentcount value=2. When the result from comparing represents that thedifference between the count values is 1, the count checking portion 54determines that data should have been correctly transferred.

[0131] Next, when the transmission count adding portion 55 is notifiedby the state change detecting portion 43 that a state has changed attime t(n−1), the transmission count adding portion 55 increments thecurrent count value=n−2 by 1, adds count value=n−1 to the TAG currentdata, and notifies the count checking portion 54 of count value=n−1.When the count checking portion 54 receives the TAG current data, thecount checking portion 54 extracts current count value=n−1 from the TAGcurrent data and compares the previous count value=n−2 with the currentcount value =n−1. When the result from comparing represents that thedifference of the count values is 1, the count checking portion 54determines that data should have been correctly transferred.

[0132] Next, when the transmission count adding portion 55 is notifiedby state change detecting portion 43 that a state has changed at timet(n), the transmission count adding portion 55 increments the currentcount value=1−by 1, adds count value=n to the TAG current data, andnotifies the count checking portion 54 of count value=n.

[0133] When it is assumed that a defect takes place on the network 24after time t(n−1), the count checking portion 54 is not notified of anevent at time t(n).

[0134] Next, when the transmission count adding portion 55 is notifiedby the state change detecting portion 43 that a state has changed attime t(n+1), the transmission count adding portion 55 increments thecurrent count value=n by 1, adds count value=n+1 to the TAG currentdata, and notifies the count checking portion 54 of count value=n+1.

[0135] When it is assumed that the defect which had taken place on thenetwork 24 at time t(n−1) or later has recovered at time t(n) or later,an event notification is transferred to the count checking portion 54 attime t(n+1).

[0136] When the count checking portion 54 is notified of the event, thecount checking portion 54 extracts the current count value=n+1 from theTAG current data and compares the previous count value with the currentcount value. In this case, since the event at time t(n) has not beentransferred to the count checking portion 54 due to the defect on thenetwork 24, the previous count value stored in the count checkingportion 54 is still n−1.

[0137] Thus, when the count checking portion 54 compares the previouscount value=n−1 with the current count value=n+1, the count checkingportion 54 detects that the difference between the count values is 2.When the result from detecting represents that difference=2, the countchecking portion 54 determines that an event notification should havebeen lost. The count checking portion 54 notifies the operator of theresult from detecting through the notifying means 25.

[0138] As mentioned above, when TAG current data is transmitted uponoccurrence of an event, the count value is counted up and the resultantcount value is added to a header portion of the transmission data. Theresultant data is transmitted. The reception side checks the countvalue. At that time, in the case that the transmission data cannot bereceived due to any defect and the transmission side has incremented thecount value by one, the count values received on the reception side arenot successive. As a result, the reception side can detect lost eventnotifications. Consequently, the reliability of the monitoring functioncan be improved.

[0139] Next, with reference to the accompanying drawings, a plantmonitoring apparatus according to a fifth embodiment of the presentinvention will be explained.

[0140] In the plant monitoring apparatus 51 shown in FIG. 10, a countvalue is added to TAG current data and the resultant TAG current data istransmitted. The reception side checks the count value. Thus, even whenfor example UDP/IP as a protocol is used, the data transmission rate canbe improved while the reliability of data transmission is prevented frombeing deteriorated.

[0141] However, in the case only that a lost event notification isdetected on the reception side, the event notification is nottransferred to the reception side. Thus, the reliability of themonitoring operation is deteriorated.

[0142] To solve such a problem, according to the fifth embodiment of thepresent invention, when the reception side detects a lost eventnotification, the reception side requests the transmission side toretransmit the event notification. Thus, even when a defect temporarilytakes place on the network, the reliability of the monitoring operationcan be improved.

[0143]FIG. 12 is a block diagram showing the structure of the plantmonitoring apparatus according to the fifth embodiment of the presentinvention. In FIG. 12, a plant monitoring apparatus 61 is composed ofthe structure of the plant monitoring apparatus 51 shown in FIG. 10, anall TAG data processing portion 65 which is disposed in a controllingdevice 63, and an all TAG data requesting portion 64 which is disposedin a monitoring device 62. The all TAG data processing portion 65acquires current data of all input points through the data input/outputportion 28 according to a request from the all TAG data requestingportion 64. Thus, making reference to the content of the TAG fixedinformation database 30 b, the all TAG data processing portion 65converts the current data of all the input points into TAG data. When alost event notification has been detected, the all TAG data requestingportion 64 requests the all TAG data processing portion 65 for currentdata of all TAGs.

[0144] When the count checking portion 54 detects a lost event accordingto the result from comparing count values, the count checking portion 54notifies the all TAG data requesting portion 64 that an eventnotification has been lost. Then, being notified that the eventnotification has been lost, the all TAG data requesting portion 64requests the all TAG data processing portion 65 for data of all theTAGs.

[0145] When the all TAG data processing portion 65 is requested for dataof all the TAGs, the all TAG data processing portion 65 acquires currentprocess data of all the TAGs and distributes TAG current data of all theTAGs to the monitoring portion 27 through the transmission count addingportion 55 and the count checking portion 54.

[0146]FIG. 13 is a flow chart showing a data acquiring method in thecase that a lost event notification is detected according to the fifthembodiment of the present invention. In FIG. 13, when the count checkingportion 54 receives TAG current data through the network 24, the countchecking portion 54 determines whether or not all TAG data is requestedaccording to the content of the transmission header of the TAG currentdata (at step S21). When the result from determining represents that allTAG data is not requested, the count checking portion 54 checks atransmission count value of the TAG current data received from thetransmission count adding portion 55 and determines whether or not anevent notification has been lost (at step S22). When the result fromdetermining represents that an event notification has been lost, thecount checking portion 54 notifies the all TAG data requesting portion64 that an event notification has been lost (at step S24). When the allTAG data requesting portion 64 is notified by the count checking portion54 that an event notification has been lost, the all TAG data requestingportion 64 requests the all TAG data processing portion 65 for all TAGdata (at step S31).

[0147] When the all TAG data processing portion 65 is requested by theall TAG data requesting portion 64 for all TAG data, the all TAG dataprocessing portion 65 searches the TAG fixed information database 30 bfor all TAGs which corresponds to the request (at step S32). Afterhaving searched for all TAGs which corresponds to the request, the allTAG data processing portion 65 inputs data through the data input/outputportion 28 according to the result from searching (at step S33) andcreates TAG current data for all the TAGs corresponding to the requestas all TAG data (at step S34).

[0148] Thereafter, the all TAG data processing portion 65 adds headerdata representing a reply to the request for all TAG data to the all TAGdata (at step S35) and notifies the transmission count adding portion 55of the all TAG data to which the header data has been added.

[0149] When receiving the all TAG data, the transmission count addingportion 55 sets an initial value 0 as a transmission counter (at stepS36) and adds transmission counter=0 to the all the TAG data. Thus, thetransmission count adding portion 55 distributes the all TAG data towhich transmission counter=0 has been added to the count checkingportion 54 through the network 24 (at step S37).

[0150] When receiving transmission data from the controlling device 63,the count checking portion 54 determines whether or not the transmissiondata is a reply containing the result corresponding to the request forall TAG data according to the header data of the transmission data (atstep S21). When the result from determining presents that thetransmission data is a reply containing the result corresponding to therequest for all TAG data, the count checking portion 54 notifies themonitoring portion 27 of the all TAG data as the latest data withoutneed to compare the transmission count=0 which has been set to the allTAG data with the previous count value (at step S23).

[0151] When receiving the all TAG data from the count checking portion54, if necessary, the monitoring portion 27 selects data to be used andnotifies the operator of the selected data through the notifying means25.

[0152] As mentioned above, the all TAG data requesting portion 64 andthe all TAG data processing portion 65 are disposed. When a lost eventnotification is detected, the all TAG data requesting portion 64requests the all TAG data processing portion 65 to acquire states of allTAGs. Thus, the all TAG data processing portion 65 notifies themonitoring portion 27 of all the TAG current data. When a defecttemporarily takes place on the network 24 and a lost event notificationcorresponding to a state change at each input point is detected, currentdata of all TAGs is acquired and treated as monitor data. As a result,the reliability of the monitoring function can be improved.

[0153]FIG. 14 is a block diagram showing a structure on which softwarethat accomplishes a plant monitoring apparatus according to anembodiment of the present invention acts.

[0154] In FIG. 14, reference numeral 71 represents a central processingunit (CPU) which performs an overall process. Reference numeral 72represents a read-only memory (ROM). Reference numeral 73 represents arandom access memory (RAM). Reference numeral 74 represents acommunication interface. Reference numeral 75 represents a communicationnetwork. Reference numeral 76 represents an input/output interface.Reference numeral 77 represents a display which displays a monitorscreen, an operation screen, alarm information, a plant video input, andso forth. Reference numeral 78 represents a printer which prints monitorinformation, operation information, and so forth. Reference numeral 79represents a sensor which detects a process signal and reads video dataand so forth. Reference numeral 80 represents an A/D conversionprocessing device which converts an analog signal which is read by thesensor 79 into a digital signal. Reference numeral 81 represents akeyboard. Reference numeral 82 represents a pointing device such as amouse. Reference numeral 83 represents a driver which drives a storagemedium. Reference numeral 84 represents a hard disk. Reference numeral85 represents an IC memory card. Reference numeral 86 represents amagnetic tape. Reference numeral 87 represents a floppy disk. Referencenumeral 88 represents an optical disc such as a CD-ROM or a DVD-ROM.Reference numeral 89 represents a bus.

[0155] A program executing editing and distributing common parameters, aprogram executing a TAG forming process, a program executing detecting astate change pertaining to a process, a program executing detecting alost event notification according to a count value, a program executingretransmitting an event notification, common parameters, deviceparameters, TAG fixed information, and so forth are stored in thestorage medium such as the hard disk 84, the IC memory card 85, themagnetic tape 86, the floppy disk 87, and/or the optical disc 88.

[0156] When these programs and data are read out to the RAM 73 from thestorage mediums, the plant can be distributively monitored on real timebasis while data at each monitoring point is consistent. In addition,the load imposed on the communication network 75 can be suppressed frombeing increased.

[0157] In addition, the program executing editing and distributingcommon parameters, the program executing the TAG forming process, theprogram executing detecting a state change pertaining to a process, theprogram executing detecting a lost event notification according to acount value, the program executing retransmitting an event notification,the common parameters, the device parameters, the TAG fixed informationand/or so forth may be retrieved from the communication network 75through the communication interface 74.

[0158] As the communication network 75 connected to the communicationinterface 74, for example, LAN (Local Area Network), WAN (Wide AreaNetwork), the Internet, an analog telephone network, a digital telephonenetwork (ISDN: Integral Services Digital Network), PHS (Personal HandySystem), or a wireless communication network such as a satellitecommunication can be used.

[0159] When the program executing editing and distributing commonparameters is started, the CPU 71 makes the display 77 display the editscreen for common parameters. When a common parameter is set on the editscreen by operating the keyboard 81, the pointing device 82, or thelike, the common parameter is distributed to each device through thecommunication network 75.

[0160] When the program executing the TAG forming process is started,the CPU 71 collects a process value at each sampling timing through thesensor 79. With reference to TAG fixed information stored in the storagemedium such as the hard disk 84, the IC memory card 85, the magnetictape 86, the floppy disk 87, or the optical disc 88, the CPU 71 groups aprocess value and information associated therewith at each samplingtiming and distributes the grouped data through the communicationnetwork 75.

[0161] When the program executing detecting a state change pertaining toa process is started, the CPU 71 compares past TAG formed data withcurrent TAG formed data to detect a state change pertaining to aprocess. Only when having detected the state change, the CPU 71distributes the current TAG formed data through the communicationnetwork 75.

[0162] When the program executing detecting a lost event notificationaccording to a count value is started, the CPU 71 adds a count valuerepresenting a transmission count to TAG formed data and transmits theTAG formed data through the communication network 75. When receiving theTAG formed data, the CPU 71 determines whether the count value added tothe received TAG formed data matches a reception count of the TAG formeddata. When they do not match, the CPU 71 causes a message representingthat to be displayed on the display 77.

[0163] When the program executing retransmitting an event notificationis started, if a count value added to TAG formed data does not match areception count of the TAG formed data, the CPU 71 requests thetransmission side to retransmit the TAG formed data through thecommunication network 75. On the other hand, when requested toretransmit TAG formed data through the communication network 75, the CPU71 acquires process data of all input points through the sensor 79,makes reference to TAG fixed information stored in the storage mediumsuch as the hard disk 84, the IC memory card 85, the magnetic tape 86,the floppy disk 87, the optical disc 88, or the like, and generates allTAG data. The CPU 71 distributes the all TAG data to the request sidethrough the communication network 75.

[0164] As was described above, according to the present invention, acommon parameter for a plurality of devices is distributed to eachdevice. As a result, the common parameter for the plurality of devicescan be changed by one edit operation. Thus, it is not necessary tochange the common parameter for each device repeatedly. Consequently,the engineering efficiency of the plant can be improved.

[0165] In addition, process information is correlated on the side whichdistributes information. The correlated process information isdistributed at a time. Consequently, it is not necessary for the side towhich the information is distributed to correlate process informationseparately transmitted. Accordingly, the process information, which hasbeen distributed to a plurality of locations, can be uniformlycorrelated. Thus, since the consistency of data between the controllingdevice and the monitoring device is improved, the reliability of themonitoring operation is also improved.

Industrial Utilization

[0166] A plant monitoring apparatus and a storage medium according tothe present invention can be produced in a plant production industry, aplant engineering industry, and so forth. Thus, the plant monitoringapparatus and the storage medium according to the present invention canbe adopted in those industries or industries that use the plantactually.

What is claimed is:
 1. A plant monitoring apparatus having a pluralityof devices configured to monitor a plant, the plant monitoring apparatuscomprising: common parameter setting means for setting a commonparameter shared by the plurality of devices; and distributing means fordistributing the common parameter to the plurality of devices.
 2. Theplant monitoring apparatus as set forth in claim 1, further comprising:a TAG database configured to store for each of the devices the commonparameter; and a device database for each of the devices configured tostore a parameter individual for each of the devices.
 3. A plantmonitoring apparatus configured to input process information from aplant and to monitor the plant, the plant monitoring apparatuscomprising: process information grouping means for grouping the processinformation according to an identifier unit; and transmitting means fortransmitting the grouped process information at a time.
 4. The plantmonitoring apparatus as set forth in claim 3, further comprising: meansfor causing the process information to be consistent according to theidentifier unit.
 5. The plant monitoring apparatus as set forth in claim3 or 4, further comprising: state change detecting means for detecting astate change of the plant according to the identifier unit, wherein thetransmitting means is configured to transmit current process informationonly when the state change of the plant has been detected.
 6. The plantmonitoring apparatus as set forth in claim 5, wherein the state changedetecting means includes change amount detecting means for detecting achange amount of a plant value of the process information according tothe identifier unit, and wherein the transmitting means is configured totransmit the current process information only when the change amountexceeds a predetermined value.
 7. The plant monitoring apparatus as setforth in any one of claims 3 to 6, further comprising: counting meansfor counting an event notification transmission count according to theidentifier unit, wherein the transmitting means is configured to add theevent notification transmission count to an event notification andtransmit the event notification to which the event notificationtransmission count is added.
 8. The plant monitoring apparatus as setforth in claim 7, further comprising: receiving means for receiving theevent notification to which the event notification transmission counthas been added; and determining means for determining a reception stateof the event notification according to a result from comparing the eventnotification transmission count and an event notification receptioncount.
 9. The plant monitoring apparatus as set forth in claim 8,further comprising: retransmission requesting means for requesting aretransmission of the event notification according to the receptionstate.
 10. A computer readable storage medium on which a program hasbeen stored, the program causing the computer to execute: collectingprocess information according to an identifier unit; and transmittingthe collected process information at a time.